Method for treating the ear, nose, sinus or throat

Abstract

Bodily tissue and structures may be protected using a fluid layer containing a mixture of chitosan and oxidized polysaccharide. The mixture forms a protective gel layer via in situ crosslinking. Compared to crosslinking using a low molecular weight aldehyde such as glutaraldehyde or genipin, oxidized polysaccharides appear to provide faster gelation while avoiding the use of potentially less bioacceptable low molecular weight aldehydes.

We claim: 
     
       1. A method for treating bodily tissue or structure in the ear, nose, sinus or throat, which method comprises:
 a) applying to such ear, nose, sinus or throat tissue or structure a fluid layer containing a mixture of (i) chitosan having a number average molecular weight before sterilization of at least about 50 kDa and (ii) an oxidized polysaccharide, and 
 b) allowing the mixture to crosslink in situ to form a protective gel layer that remains exposed to air or other nearby gases, reduces adhesions to anatomy, and has a residence time of one day to four weeks. 
 
     
     
       2. A method according to  claim 1  comprising applying the fluid layer to a nasal or sinus cavity. 
     
     
       3. A method according to  claim 1  comprising applying the fluid layer to a middle or inner ear. 
     
     
       4. A method according to  claim 1  comprising applying the fluid layer to throat tissue. 
     
     
       5. A method according to  claim 1  comprising applying the fluid layer to mucosal tissue. 
     
     
       6. A method according to  claim 1  comprising applying the fluid layer from a multiple-barrel syringe. 
     
     
       7. A method according to  claim 1  comprising applying the fluid layer by spraying. 
     
     
       8. A method according to  claim 1  wherein the chitosan is an unmodified chitosan or a chitosan salt. 
     
     
       9. A method according to  claim 1  wherein the chitosan is a chitosan derivative. 
     
     
       10. A method according to  claim 1  wherein the oxidized polysaccharide comprises oxidized starch. 
     
     
       11. A method according to  claim 1  wherein the oxidized polysaccharide comprises oxidized cellulose. 
     
     
       12. A method according to  claim 1  wherein the oxidized polysaccharide comprises oxidized chitin, oxidized chitosan, oxidized chondroitin sulfate, oxidized dextran, oxidized glycogen or oxidized hyaluronic acid. 
     
     
       13. A method according to  claim 1  wherein the chitosan and oxidized polysaccharide are combined in a ratio of about 10:1 to about 1:20. 
     
     
       14. A method according to  claim 1  wherein the chitosan and oxidized polysaccharide are combined in a ratio of about 3:1 to about 1:5. 
     
     
       15. A method according to  claim 1  wherein the chitosan is a low molecular weight material having a number average molecular weight of about 50 to about 200 kDa. 
     
     
       16. A method according to  claim 1  wherein the chitosan is a medium molecular weight material having a number average molecular weight of about 200 to about 500 kDa. 
     
     
       17. A method according to  claim 1  wherein the chitosan is a high molecular weight material having a number average molecular weight greater than about 500 kDa. 
     
     
       18. A method according to  claim 1  wherein the fluid layer remains a gel during biodegradation or bioresorbtion. 
     
     
       19. A method according to  claim 1  wherein the protective gel layer is biodegradable or bioresorbable without shedding large solid chunks. 
     
     
       20. A method according to  claim 1  wherein the fluid layer contains chitosan and oxidized polysaccharide in a combined amount of about 1 to about 10 wt. % of the fluid layer. 
     
     
       21. A method according to  claim 1  wherein the fluid layer consists essentially of chitosan, oxidized polysaccharide, a solvent selected from water and alcohols, and an optional buffering agent.